Page 1
Vol. 4, No.3 August 2013 http://www.comm.ntu.edu.tw [email protected]
Technology Developed in GICE
In this issue
GICE Honors
Message from the
Director
Technology
Developed in GICE
- Digital Terrestrial
Television
Switchover in
Taiwan – An
Engineering
Professor’s
Perspective
- A Planar
Microwave Power-
combined Amplifier
Using
Metamaterials
Apply to GICE
Invited Talk
Activities
- TEMIAC Technical
Forum- New Radar
Technology for Civil
Applications
- 2013 A visit to
Panasonic Taiwan
Corner of Student
News
1
2
1-3
4-6
6
6-7
7
7-8
8
Digital Terrestrial Television Switchover in Taiwan – An Engineering
Professor’s Perspective
from Communication and Signal Processing Group
Since the beginning of July 1st,
2012, Terrestrial Television (TTV)
signals all over Taiwan have been
all digital. Analog TTV signals that
served Taiwanese people for
almost 50 years completely went
into history. The switchover freed
spectrum in the bands of 76-
88MHz, 174-210MHz and 608-
710MHz as parts of “digital
dividends” and laid the foundation
of High Definition TV broadcasting.
I, an engineering professor-turned
commissioner of National
Communications Commission
(NCC), had the privilege to
participate in the last two years of
switchover preparations and to
eyewitness this milestone event in
TV history of Taiwan.
NCC took over the mission of DTTV
switchover (DSO) at the end of
2009 from the Government
Information Office and I accepted
the challenges of DSO tasks at the
first day into the commissioner’s
office. DTTV signals have been on
air in Taiwan since 2003 and there
had been more than 2.5 million
standard definition (SD) digital TVs
or set top boxes sold. As cable TVs
had penetrated to more than 80% of
households and the main TTV
channels are must-carries by cable
TV, the DSO mission seemed to be
simply “turning the analog TTV signals
off and releasing the corresponding
spectrum” at the policy level. In
execution, there involved many
challenges.
Maintaining the viewing rights of the
analog TTV viewers is the
fundamental requirement for DSO.
How to raise DTTV signal coverage to
the whole country, either in the
distant rural areas or in the
shadowed corners of metropolitan
areas, poses the first challenge. To
speed up the construction of gap
fillers or boosters, NCC team needed
to coordinate with local
governments at either city, county,
town or village level, TV
broadcasters, and even
telecommunication operators,
especially in solution selection and in
locating and acquiring the site for
radio towers. During 2010 to mid
2012, NCC raised DTTV coverage to
more than 96% of population by
GICE Honors
Prof. Ruey-Beei Wu
The Outstanding
Research Award of Pan
Wen Yuan Foundation
Prof. Lin-shan Lee
The Outstanding In-school
Service Award for
Teachers of National
Taiwan University
(continued on page 2)
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2 GICE NEWSLETTER VOL. 4, NO.3 August 2013
Fig. 2 DTTV and satellite TV for aborigine’s households in rural
areas
What would be government’s household assistance
scheme for DSO? Who is eligible? After the
Executive Yuan. set the policy of free installation of
a set top box per low income household, how
should it be carried out effectively? How about
many none low-income households that had
analog TTV as the only source of TV programs but
could not afford the set top box and/or antenna?
All these posed the second challenge. The NCC
team designed the procurement specifications
that a set top box must have the new features of
compliance to DVB-T H.264 (HD) standard, parental
control and less than 1 W standby power
consumption and that a remote controller should
be easy to use for the senior citizens. Based on the
low income household list provided by the Ministry
of the Interior, NCC contracted and managed
three regional contractors to provide 100,000+ low
income households nation-wide with DSO
assistance from August 2011 to June 2012 (Fig. 3).
Fig.3 Set top box and antenna installation assistance to low
income household
Promotion to and education (P&E) of the general
public about DSO had been critical to successful
policy implementation but is what I was unfamiliar
and inexperienced with. In principle, GIO was in
charge of P&E at the concept level while NCC was
responsible for technical assistance. In practice,
there needed many coordination efforts between
the two organizations. Besides government
jointly completing 53 gap fillers/boosters with HD
modules with local governments. In conjunction
with the use of satellite TV broadcasting, digital TV
signals cover the whole country (Fig. 1& Fig.2).
Fig. 1 Gap filler construction (a site in Peng Hu County)
Message from the Director
2012 is a fruitful year for GICE. Several research
outcome and developed technologies have
been well recognized in international society.
Three faculties of GICE, Prof. Homer Chen, Prof.
Wanjiun Liao, and Prof. Kwang-Cheng Chen, are
elected as IEEE Distinguished Lecturers. Our
master program student, Chiu-Chih Chou,
received the Best Student Paper Award in 21st
IEEE Electrical Performance of Electronic
Packaging and Systems (EPEPS). It is the fourth
paper to be awarded as best paper award in
IEEE prestigious conferences in past 3 years. The
honors demonstrate again GICE’s momentum in
pursuit of academic excellence. Hopefully, you
enjoy the reading of GICE Newsletter.
Happy New Year!
PFD/CPLoop
Filter
Frequency Divider
/N
RF
VCO
Vital-sign
baseband signal
Control
Power
Divider
Circulator
Target
Transmitting
Antenna
Receiving
Antenna
Reference
Frequency
Technology (continued from page 1)
(continued on page 3)
Message from the Director
Dear Colleagues and Friends,
This issue reports several interesting topics. Prof.
Shi-Chung Chang in GICE has served as the
Commissioner of National Communications
Commission (NCC) in Taiwan during 2009 – 2012.
He reviews the whole process in government
policy and execution level for the digital
terrestrial television switchover in Taiwan, which is
successfully completed in June 30, 2012 and is a
milestone in TV history of Taiwan. Prof. Chang
shares the difficulties and lessons learned in this
process. Another interesting technology
proposed by Prof. Tah-Hsiung Chu is a novel
microwave power-combined amplifier based on
metamaterials. A prototype with excellent
performance is also demonstrated in this report.
In addition, several GICE activities with
international interactions with academia and
industries also appear in this issue.
Hopefully, you enjoy the reading of GICE
Newsletter.
My Best wishes,
Tzong-Lin Wu
Tzong-Lin Wu
Professor & GICE Director
Page 3
3
Technology (continued from page 2)
sponsored advertisements over major media,
promotions in large-scale events and 3C chain
stores and distribution of flyers, posters and banners
by local governments, NCC had hundreds of
workshops at townships or villages to explain what
DTTV is about and demonstrate to both the public
servants and the general public about the
preparation and DIY for DSO(Fig. 4). Ministry of
Economic Affairs helped informed set top box
suppliers of manufacturing or importing DVB-T H.264
(HD) set top box only starting from year 2011.
Furthermore, based on the design and experience
of viewer service centers of the 5 TTV broadcasters,
NCC set up a call center to answer DSO related
questions and provided installation assistance to
the home when needed. The center served over
100 thousands of call requests since July 1st, 2011.
Fig.4 Promotion of DTTV and switchover
The final switchover was by stage and by region
according to regional readiness, which started with
the central region on May 7, 2012, then eastern,
southern, and finally the northern region at noon,
June 30, 2012. To notify the unprepared, full-screen
and signal-off notifications of regional DSO had
been broadcasted in each region over all the
analog channels 4 weeks before the regional
switchover date. As a result, unprepared viewer
call-in rate within 24 hours of analog signal switch
off is approximately 0.08% in the central region
(1603 out of 2.1 million households), which is well
compatible with those of Demark (0.14%) and
Japan (0.36%). Similar to other countries using by-
stage-and-by-region strategies such as Austria and
Czech Republic, the switchover of remaining regions
went the later, the smoother.
There are many lessons learned from DSO. In
specific, I would like to share a few as conclusions
from an engineering professor perspective:
1. When the target switchover date was moved, in
mid 2011, from December 31 to June 30, 2012,
the adjustment of budget plan did not closely
align with the task plan and caused many
challenges to later implementation.
2. Pilot experiments and dynamic feedback are
key to effective execution control and
management. Pilot experiments such as the one
in Pinglin township, summer 2010, and then the
ones in Da-Chia district, I-Lan county, Chia-Yi
county, etc., allowed NCC team to clearly
identify the needs by the TTV viewers, the
concerns of local governments and how to plan
the collaboration for large-scale switchover.
NCC workshops, visit to local governments,
viewer phone surveys and call center services,
and comments from the media had provided
very valuable feedbacks to adjust the detailed
execution.
3. Effective identification of the households that
have analog TV channels as the sole source of
TV programs is an interesting research problem
because of the rareness of such viewers.
4. Rationality assumption by classical game theory
may not fit very well in modeling individuals but
fits quite well in modeling organizations or
companies. The contract design for
management of household assistance
contractors is a real example. There are many
cases that can be abstracted into my teaching
materials for the course on “Information, Control
and Games.”
In conducting DSO tasks, I had been to many
beautiful places in Taiwan and talked to and got
help from many kind people, which is a very
enjoyable experience. I appreciated very much this
opportunity to contribute as a member of the NCC
DSO team to the people and the land.
For more information please contact:
Professor Shi-Chung Chang
Email: [email protected]
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4 GICE NEWSLETTER VOL. 4, NO.3 August 2013
Technology
(c)
Fig. 1 (a) Structure, (b) schematic, and (c) circuit of a planar
nine-way power-combined amplifier with R representing RH cell
and L representing L cell.
This article presents a planar nine-way metamaterial
power-combined amplifier based on this
characteristic. The planar metamaterial power
dividers contain positive refractive index (PRI)
material and zero refractive index (ZRI) material. The
PRI material is composed of two-dimensional (2-D)
RH unit cells, while the ZRI material is realized by
using LH unit cells operated at the infinite
wavelength frequency to give the zero-phase shift
characteristic. Due to its uniform isolation
characteristics of the metamaterial power
dividing/combining structure, its graceful
degradation performance is independent of the
amplifier failure sequence.
Fig. 1 shows the structure, schematic, and circuit of
a planar nine-way metamaterial power-combined
amplifier. As shown in Fig. 1(a), the input port is at
focal point O. A cylindrical wave to planar wave
conversion occurs at the left-side PRI-ZRI interface
and attains an equal magnitude and phase
distribution in the ZRI material to the collinearly
aligned amplifiers along the dashed line UV . The
amplification is obtained at the dashed line ' 'U V
then converted to a cylindrical wave through the
right-side ZRI-PRI interface to the output port at focal
point 'O . Specifically, a planar PRI-ZRI-PRI lens with
power dividing and combining characteristics is
integrated with nine amplifiers as a planar
metamaterial power-combined amplifier.
As shown in Fig. 1(b), the semi-circular interface
Due to the power capacity of solid-state devices,
power combining of multiple devices becomes
necessary as a higher output power level is required.
Therefore, development of microwave power
dividing/combining techniques [1] of solid-state
devices to achieve low loss and high combining
efficiency is desirable. As the number of active
devices increases, N-way power dividing/combining
structures, such as Wilkinson [2] and radial [3]
structures in a parallel configuration, are usually used
due to compactness. These structures do not have
the disadvantage of increasing loss with the number
of active devices existed in chain and tree
configurations. However, their main problem is
having non-collinearly aligned multiple ports to
make their integration with active devices in a
planar structure difficult.
Recently, metamaterials with negative refractive
index having left-handed (LH) propagation behavior
are extensively applied to microwave devices [4].
They are mainly composed of one-dimensional right-
handed (RH) and LH transmission lines called
composite right/left-handed (CRLH) transmission
lines. By properly operating CRLH transmission lines at
the infinite wavelength frequency, metamaterials
can have a zero-phase shift characteristic along the
structure to give an equal magnitude and phase
distribution.
O PRI
material
'O
U
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'U
'V
ZRI
material
PRI
material
ZRI
material
(a)
R R
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LLR
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RRR
RRR
RR
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2
3
4
5
6
7
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9
Divider Structure Combiner StructureAmplifier
x
y
(b)
A Planar Microwave Power-combined Amplifier Using Metamaterials
from Electromagnetics Group
(continued on page 5)
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5
Technology (continued from page 4)
environments. However, the probe measurement
can clearly reveal the performance of the nine-way
metamaterial power divider and combiner and the
nine amplifiers.
(a)
(b)
(c)
Fig. 2 Measured results of (a) the output power, power gain, and
PAE, (b) magnitude of 21S in dB with respect to the input port
and (c) cosine(phase).
Due to the infinite wavelength phenomenon,
constant bution at the 7th and the 8th columns is
obtained from the 4th row to the 7th row, and 21S at
these four rows is shown higher than that of the
other rows. It may result from the non-uniformity of
nine amplifiers. Furthermore, the graceful
degradation characteristic of this nine-way power-
combined amplifier is experimentally demonstrated
and shown differently as those of using radial and
planar power dividers and combiners.
19 20 21 22 23 24 25 26 27 28 29 305
10
15
20
25
30
35
40
45
50
55
60
Outp
ut
pow
er
(dB
m)
and p
ow
er
gain
(dB
)
Input power (dBm)
Output power
Power gain
PAE
5
10
15
20
25
30
35
40
45
50
55
60
PA
E (
%)
between PRI and ZRI materials is approximated in a
staircase manner. Each of the power divider and
combiner includes 9 × 7 cells. Ports 1 and 2 located
at the central RH unit cells of two PRI materials are
the input and output ports, respectively. The
remaining ports which are not indexed are open
circuits. Nine amplifiers are directly connected to
the divider output ports and the combiner input
ports.
A nine-way power divider/combiner is designed on
a 1.575-mm-thick RT/Duroid 5880 substrate with
2.2r and tan 0.0009 . The operating frequency
is 1 GHz. The size of RH and LH unit cells is given by 10
mm 10 mm. The characteristic impedance of
transmission line used in RH and LH cells is
100 oR oLZ Z . By considering the parasitic effects
of surface mounted device (SMD), shunt MuRata
0603 36 nH SMD inductors and series 0402 5.6 pF SMD
capacitors are used to realize LH unit cells with zero-
phase shift characteristics. The amplifiers are Hittite
HMC452ST89E 1 Watt power amplifiers. The nine-way
power-combined amplifier circuit is shown in Fig.
1(c).
Fig. 2(a) shows the measured results of output
power, power gain, and PAE of the nine-way power-
combined amplifier. The output power of 38.83 dBm
at 1 dB gain compression point is obtained as the
input power is 26.83 dBm, and the corresponding DC
bias voltage and current are 5 V and 3.586 A to give
a PAE about 40%. The power combining efficiency is
85%.
Fig. 2(b) shows the active probe measured results of
21S at the central node of each cell. The excitation
source at the 5th row and the 1st column gives
21 1.1 dBS , and 21S values along the 5th row for
the 7th, 8th, and 14th columns are -6 dB, 0 dB, and
7.1 dB, respectively. This indicates that a similar
magnitude dividing and combining characteristics
for power divider and combiner is obtained, and the
amplification of 21S from the 7th column to the 8th
column is clearly observed.
Note the 21S measured results show that the gain
values of the amplifier only and the power
combined amplifier are 6 dB and 8.2 dB,
respectively, which do not quantitatively agree with
the results of 14.45 dB for a single amplifier and 13 dB
for the power-combined amplifier from S-parameter
measurements. This is due to that the measured
results given in Fig. 2(b) are the probed fringing fields
radiated from the circuit near the central node of
each RH and LH unit cells. They are affected by the
probe characteristics, circuit components and (continued on page 6)
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6 GICE NEWSLETTER VOL. 4, NO.3 August 2013
(continued on page 7)
Technology (continued from page 5)
Invited Talk Some Recent Developments in the Finite Difference Time Domain Method for
Efficient Solution of Radiation and Scattering Problems Lecturer : Prof. Raj Mittra
With the advent of sub-micron technologies and
increasing awareness of Electromagnetic
Interference and Compatibility (EMI/EMC) issues,
engineers are often interested in full-wave solutions
of the complete system, that takes in to account a
variety of environments in which an antenna or a
scatterer may be located. However, deriving full
wave solutions of such complex problems is
challenging, especially when dealing with problems
that involve multi-scale geometries with very fine
References
[1] K. J. Russell, “Microwave power combining techniques,” IEEE
Trans. Microw. Theory Tech., vol. MTT-27, no. 5, pp. 472–478, May
1979.
[2] E. Wilkinson, “An N-way hybrid power divider,” IRE Trans.
Microw. Theory Tech., vol. MTT-8, no. 1, pp. 116–118, Jan. 1960.
[3] A. E. Fathy, S. W. Lee, and D. Kalokitis, “A simplified design
approach for radial power combiner,” IEEE Trans. Microw. Theory
Tech., vol. 54, no. 1, pp. 247–255, Jan. 2006.
[4] C. Caloz and T. Itoh, Electromagnetic Metamaterials:
Transmission Line Theory and Microwave Applications, New York:
Wiley, 2005.
For more information please contact:
PHD Student: Wei-Chiang Lee
Adviser: Professor Tah-Hsiung Chu
Email: [email protected]
(continued on page 7)
Apply to GICE
Page 7
7
TEMIAC Technical Forum- New Radar Technology for Civil Applications
Owing to the progress of semiconductor process
and a variety of emerging wireless services, the
radar technology for civil applications has
prevailed in the public mind and drawn extensive
attention in recent years. This season seminar is
organized by Taiwan Electromagnetic Industry-
Academia Consortium (TEMIAC), Graduate Institute
of Communication Engineering (GICE) of National
Taiwan University, and Communication Research
Center (CRC) of National Taiwan University
together. The enthusiastic attendees from various
fields are more than one hundred. The organizers
are honored to invite many experts from industry
and academy to give inspiring speeches about
radar applications to safety surveillance, process
automation, homeland security, automotive safety,
vital-sign monitoring, and smart home appliances.
The technical background, economic value and
future prospect of the addressed topics are
extensively illustrated. In addition to the speeches, a
panel discussion is provided for the invited experts
and audiences to share their perspective on the
challenges and opportunities of radar technology
and look forward to future cooperation over the
coming years. Through the current system
integration and DSP techniques, radar can be
embedded in an electronic product more easily to
develop potential killer applications. We wish the
abundant information shared in this season seminar
will benefit upgrading the domestic electronic
industries to promote their international
competitiveness.
Panel discussion- Five experts from industries and academia are
invited to share opinions on the challenges and opportunities of
radar technology.
Over 130 participants from industries and academia attended
this seminar.
Activities
features. Even the well-established methods, such
as the time domain technique FDTD (Finite
Difference Time Domain Method), and the
frequency domain methods FEM and MoM, are
often pushed to the limits of their capabilities when
attempting to solve such problems. In an attempt to
meet such challenges, we present some novel
techniques, which hybridize the the Dipole Moment
(DM) Approach and Recursive Update in
Frequency Domain (RUFD) with the FDTD. In
addition, we address the so-called "low-frequency"
problem, which presents a formidable challenge to
the not only to the FDTD, but to FEM and MoM
algorithms as well.
2013 A visit to Panasonic Taiwan
2013 May 10, the delegation led by director Tzong-
Ling Wu called on the president of Panasonic
Taiwan, Mr. Hong-Min Hong, and general manager
Mr. Akihiro Nakatani. The delegation visited the (continued on page 8)
factory in Da-Yuan, Taoyuan, which produces Any
Layer Interstitial Via Hole (ALIVH) for Hi-tech mobile
device such as smartphones, and interchanged
Invited Talk (continued from page 6)
Page 8
8 GICE NEWSLETTER VOL. 4, NO.3 August 2013
National Taiwan University
Graduate Institute of
Communication Engineering
No.1, Sec.4, Roosevelt Road,
Taipei 10617, Taiwan
Phone
+886-2-3366-3075
Fax
+886-2-2368-3824
E-mail
[email protected]
Visit us at:
http://www.comm.ntu.edu.tw
Editor in Chief
Prof. Hung-Yu Wei
Editors
Chih-Hao Wei
Yi-Ru Guo
Prof. J. C. Chiao
University of Texas – Arlington, USA
Topic: Implantable wireless medical
devices and systems
National Taiwan University
Graduate Institute of
Communication Engineering
No.1, Sec.4, Roosevelt Road,
Taipei 10617, Taiwan
Phone
+886-2-3366-3075
Fax
+886-2-2368-3824
E-mail
[email protected]
Visit us at:
http://www.comm.ntu.edu.tw
Editor in Chief
Prof. Hung-Yu Wei
Editors
Joyce Jou
Yi-Ru Guo
Corner of Student News by Hung-Chuan Chen
ideas.
In 1996, Panasonic developed ALIVH, which was a
breakthrough for mobile device that stress on space
efficiency. It was a great opportunity to have the
sight of ALIVH’s automatized production and to get
to know its technical aspect. Meanwhile, seven
professors, whose expertise cover from
chip/package design, antenna design, microwave
and millimeter wave IC design etc., shared their
researches with management and technique team
of Panasonic Taiwan. Hoping this chance will lead to
a long-term corporation of technique development,
personnel training and industry promotion between
Thanks for the great support from National Science Council. A
wonderful chance to be an intern at the world-organized and over-
100-year company, IBM in the US, is coming to my life. With the
terrific opportunity, I can understand how the prestigious and
worldwide company operates. Besides, many extraordinary first
experiences occurred during the internship.
At IBM, the site area is really large and it is hard to believe that it
takes long walk over 15 minutes from office to lab for taking
experiments. In addition to the gigantic size of the site area, it is also
amazing to collaborate with people around the world. I had
experiences in working with people in India and Italy as well as
getting assistance from Dublin in Ireland. This is the situation I have
never thought when I study in Taiwan. Moreover, I can have several
opinions about the work from different point of view based on the
culture difference and personal experience. Here, it is prevalent to
have conference call or meeting with people from different states in
the US, and even people from various countries including Japan,
Russia, and England, to discuss the same topic. Furthermore, people
work here can choose any place where they can feel comfortable
and do work efficiently. They can work in the company, at home,
even in a coffee shop. This is totally opposite to the work style we
have in our country.
The different culture and life style here bring me many first
experiences and surprising moment. One of them is to breathtakingly
see the snow in the winter. Even though it was really cold outside, the
exciting emotion warmed up my body. House and road were
covered with the white snow and it was very sparkling. However, it is
pretty dangerous to drive on a snow day. The bad weather let the
car frozen and the sleet covered the windshield to shield my view.
Sometimes, I can only peek through it to drive on the slippery road,
so I have to drive very slowly, even on the highway. Without the
developed mass transportation system here, it usually needs long
driving over 4 or 5 hours by car to travel from cities to cities. Among
the trips, I have attended some sports games and enjoyed the
atmosphere of watching the triple-A championship baseball game.
Indeed, it is really fascinating to support the player (Che-Hsuan Lin)
who also comes from Taiwan in person during the game. Therefore, I
sincerely appreciate this great opportunity and deeply cherish the
wonderful experience here.
Activities (continued from page 7)
GICE NTU and Panasonic Taiwan.